The present invention relates to an intravenous needle assembly in which the needle is retractable into the assembly.
Intravenous needle assemblies have long been utilized in the medical practice and are designed for insertion into blood vessels and similar passageways or cavities in the body, to permit infusing or withdrawing fluids. An intravenous needle of this type is described, in one particular specialized embodiment thereof, in U.S. Pat. No. 3,064,648, issued Nov. 20, 1962 to A. F. Bujan. In this device, a pair of flexible wings are utilized to fix the intravenous needle to the scalp of a patient. The needle is fixed to the flexible wings, and covered by a sheath prior to use. After utilization, the needle point is exposed and so presents a hazard during subsequent handling and disposal.
U.S. Pat. No. 4,935,011, issued Jun. 19, 1990 to J. Martin Hogan describes a sheath which may be utilized in conjunction with an intravenous needle to enclose the needle after usage so as to protect persons subsequently handling the needle against accidental sticks. The needle has a winged or butterfly housing and a sharpened cannula fixed to the housing so as to always extend therebeyond. The protective sheath encloses the wings and the cannula after use and, consequently, is comparatively bulky, as well as being relatively complex in its utilization, requiring folding and the like in order to enclose the needle. Thus, the protective sheath of U.S. Pat. No. 4,935,011 is essentially an auxiliary appliance for use with a conventional butterfly cannula, for enclosing the cannula and the housing upon which the cannula is mounted after use to avoid accident sticks.